John Lee

It's from the centre of the crankshaft to the top of the rocker cover. If you look at the link I provided you would see this example:

If you use the Internet Archive https://web.archive.org/ you can see older versions of the Laser Engines website which give contemporary data for the models of that era. EG from 2010 https://web.archive.org/web/20100213124011/http://www.laserengines.com/spec.htm

Well, yes & no! If you check out Steve Webb's 2 stroke Glow Plug page you will see that they are available from £4.50 up to about £20 each.

Deleting the names will not delete all the other attributes in that model memory, so any reverse, expo, etc etc will still remain. You need to do a 'Data reset' as described in section 3.8. It may help to appreciate that the transmitter has two separate, but interlinked, software menus. They are the 'Set up Mode' and the 'Function Mode'. They are described on pages 26 & 27 of the manual. To enter the 'Set up mode' you press & hold the Up & Down buttons before switching on the set, to enter the 'Function Mode' you press the Up & Down buttons simultaneously when the set is already switched on. To reverse any servo or the throttle you need to be in the 'Function Mode' and then follow as Peter described.

No No need for a holder. The discharge to zero takes place outdoors on a concrete slab.

1550387430392308810.pdf This is the manufacture's data sheet for those cells. I had a Rx pack of them sold by Component Shop but scrapped it after a year or two. I've otherwise stayed with genuine Panasonic 2000mAh Enerloops for AA NiMh, the oldest of which will be 14 years old in June this year and still going strong.

Very much like Leccy's, I just choose the appropriate connector for the battery.

According to the manufacturer's UK site Vapex cells have a capacity of 2500mAh and this is rated at a discharge rate of 0.2C (500mA)

It is what it is & I'm afraid wishing for a simple consecutive list of actions is just not going to happen. It's pre YouTube so I very much doubt you will get help there and you are pretty much stuck with the manual. You may want to search on the RCGroups, RCUniverse & Flying Giants forums where there were many discussions 20 years ago on how to do things. They are US forums so search using 'JR8103' But to get you started from memory & the manual: First thing is to switch on whilst holding both the up & down buttons: Then pick the model you want Then 'Select' Then back out

It was about 20 years ago that I changed the battery so I'm afraid I can't recall exactly. But when you remove the back of the transmitter it can be found soldered on one of the PC Boards. As to changing models Neddy I'd refer you to Section 3.4 on page 28 of the manual 'Model Select (System Set-Up Mode)'. The 3810 was a great set in its time, I had two of them. But it is 1990's technology and the programming is anything but intuitive, with seemingly random pressing of the 8 buttons, sometimes several at a time. Things have progressed enormously since then and you need to 'unlearn' what to expect from a set nowadays to get to grips with the operating system. Back then I carried the manual with the transmitter and often had to refer to it to remind myself how to do relatively simple tasks.

Note the information on page 18 about the lithium memory battery. Given the age of the radio it is likely to need replacing, unless already done in the last couple of years. As you are likely to lose all the model memories when it is replaced it may be worth your while doing this before you otherwise start using the set. Despite the warnings in the manual I found it straightforward to replace the battery and by acting quickly I was able to preserve the volatile memory. I'd recommend that you buy a tagged battery (CR2032) or alternatively a tagged battery holder for the job. An online search ('replace lithium memory battery on JR radio') will give you more guidance. It was a hot topic in its day, 10-15 years ago.

Obtaining Methanol will be the least of your problems in running IC engines. I only started to realise how big the market is when one of our members got a job running a methanol production plant in the Philippines a couple of decades ago. Methanol has numerous industrial uses and a quick search indicates that the global market is worth about $40 Billion and is in the region of 120 million metric tons.

Whilst I moved over from IC to electric flight a few years ago I'm sure that IC will remain a viable option for those that prefer that motive power. While cars replaced horses, we still have horse riding. Railways usurped the canals but we still have an active inland waterways life. Internal combustion replaced steam but we still have traction engine rallies The world is ever changing but there is always room for those that hanker after an older technology.

See page 14 of the BMFA Booklet. Quite old now but still very relevant. Battery Safety Booklet - June 2014.pdf

Having had a number pull out of their mountings I now use these which have a self-adhesive coating: https://www.first4magnets.com/circular-disc-rod-c34/8mm-dia-x-1mm-n35-neodymium-easypeel-adhesive-magnet-0-39kg-pull-p2988#ab_1_1|ps_2_1210 However I still epoxy or cyno them in place. The self adhesive is not strong enough on its own with the materials we use on our models but combined with glue they are pretty secure.